Central obesity associates with renal hyperfiltration in the non-diabetic general population: a cross-sectional study

• Main Authors: Stefansson, Vidar, Schei, Jørgen, Jenssen, Trond, Melsom, Toralf, Eriksen, Bjørn
• Format: Article in Journal/Newspaper
• Language: English
• Published: BioMed Central Ltd. 2016
• Subjects: Body mass index; Chronic kidney disease; Glomerular filtration rate; Glomerular hyperfiltration; Waist circumference; Waist-hip ratio; The Waist; Tromsø
• Online Access: http://www.biomedcentral.com/1471-2369/17/172

Abstract Background Obesity is a risk factor for end-stage renal disease. Renal hyperfiltration, defined as an abnormally high glomerular filtration rate (GFR), is a link in the causal chain between diabetes and chronic kidney disease. Whether obesity is associated with hyperfiltration in the non-diabetic general population, remains unresolved due to a lack of consensus regarding the definition of hyperfiltration and the limited precision of high-range GFR estimations with creatinine and/or cystatin C. Methods 1555 middle-aged participants without diabetes, renal or cardiovascular disease were enrolled from the general population in the Renal Iohexol Clearance Survey from the 6th Tromsø Study (RENIS-T6) between 2007 and 2009. Obesity was assessed using the body mass index (BMI), waist circumference (WC) and the waist-hip ratio (WHR). GFR was measured by iohexol clearance. Dichotomous variables for hyperfiltration were based on two alternative definitions using unadjusted GFR (mL/min) above the 90th percentile. The 90th percentile was age-, sex- and height-specific in one definition and age-, sex-, height- and weight-specific in the other. Results In multivariable adjusted logistic regression models, only WHR was consistently associated with hyperfiltration based on both definitions. For the definition based on the age-, sex-, height- and weight-specific 90th percentile, the association with the WHR (odds ratios (95 % confidence intervals)) for hyperfiltration was 1.48 (1.08–2.02) per 0.10 WHR increase. Conclusions Central obesity is associated with hyperfiltration in the general population. The WHR may serve as a better indicator of the renal effects of obesity than BMI or WC.